Notes on the STM32F4 Discovery Board
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http://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/mcu-eval-tools/stm32-mcu-eval-tools/stm32-mcu-discovery-kits/32f429idiscovery.html
http://www.digikey.com/product-detail/en/STM32F4DISCOVERY/497-11455-ND/2711743


LK Debug/Console UART
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- USART1 is used
- TX is A9
- RX is A10
- both are on the P1 header near the top


Using external SWD debug
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- Remove jumpers from CN3 4-pin header (near mini-usb connector)
- CN3 pin2 is SWCLK
- CN2 pin4 is SWDIO
- GND is available on P2, nearby